<?php

namespace Cart\Api;
/**
 * 仿写CodeIgniter的购物车类
 * 购物车基本功能
 * 1) 将物品加入购物车
 * 2) 从购物车中删除物品
 * 3) 更新购物车物品信息 【+1/-1】
 * 4) 对购物车物品进行统计
 *    1. 总项目
      2. 总数量
      3. 总金额
 * 5) 对购物单项物品的数量及金额进行统计
 * 6) 清空购物车
 *
 * @author quanshuidingdang
 */
class Cart {
    //物品id及名称规则,调试信息控制
    private $product_id_rule = '\.a-z0-9-_';    //小写字母 | 数字 | ._-
    private $product_name_rule = '\.\:a-z0-9-_';//小写字母 | 数字 | ._-:
    private $debug = TRUE;
     
    //购物车
    private $_cart_contents = array();
     
    /**
     * 构造函数
     *
     * @param array
     */
    public function __construct() {
        //是否第一次使用?
        if(isset($_SESSION['cart_contents'])) {
            $this->_cart_contents = $_SESSION['cart_contents'];
        } else {
            $this->_cart_contents['cart_total'] = 0;
            $this->_cart_contents['total_items'] = 0;
        }
         
        if($this->debug === TRUE) {
            //$this->_log("cart_create_success");
        }
    }
     
    /**
     * 将物品加入购物车
     *
     * @access  public
     * @param   array   一维或多维数组,必须包含键值名: 
                        id -> 物品ID标识, 
                        qty -> 数量(quantity), 
                        price -> 单价(price), 
                        name -> 物品姓名
     * @return  bool
     */
    public function insert($items = array()) {
        //输入物品参数异常
        if( ! is_array($items) OR count($items) == 0) {
            if($this->debug === TRUE) {
                $this->_log("cart_no_items_insert");
            }
            return FALSE;
        }
         
        //物品参数处理
        $save_cart = FALSE;
        if(isset($items['id'])) {
            if($this->_insert($items) === TRUE) {
                $save_cart = TRUE;
            }
        } else {
            foreach($items as $val) {
                if(is_array($val) AND isset($val['id'])) {
                    if($this->_insert($val) == TRUE) {
                        $save_cart = TRUE;
                    }
                }
            }
        }
         
        //当插入成功后保存数据到session
        if($save_cart) {
            $this->_save_cart();
            return TRUE;
        }
         
        return FALSE;
    }
     
    /**
     * 更新购物车物品信息
     *
     * @access  public
     * @param   array
     * @return  bool
     */
    public function update($items = array()) {
        //输入物品参数异常
        if( !is_array($items) OR count($items) == 0) {
            if($this->debug === TRUE) {
                $this->_log("cart_no_items_insert");
            }
            return FALSE;
        }
         
        //物品参数处理
        $save_cart = FALSE;
        if(isset($items['rowid']) AND isset($items['qty'])) {
            if($this->_update($items) === TRUE) {
                $save_cart = TRUE;
            }
        } else {
            foreach($items as $val) {
                if(is_array($val) AND isset($val['rowid']) AND isset($val['qty'])) {
                    if($this->_update($val) === TRUE) {
                        $save_cart = TRUE;
                    }
                }
            }
        }
         
        //当更新成功后保存数据到session
        if($save_cart) {
            $this->_save_cart();
            return TRUE;
        }
         
        return FALSE;
    }
    public function delete($rowid) {
        unset($this->_cart_contents[$rowid]);
		$this->_save_cart();
    } 
    /**
     * 获取购物车物品总金额
     *
     * @return  int
     */
    public function total() {
        return $this->_cart_contents['cart_total'];
    }
     
    /**
     * 获取购物车物品种类
     *
     * @return  int
     */
    public function total_items() {
        return $this->_cart_contents['total_items'];
    }
     
    /**
     * 获取购物车
     *
     * @return  array
     */
    public function contents() {
        return $this->_cart_contents;
    }
     
    /**
     * 获取购物车物品options
     *
     * @param   string
     * @return  array
     */
    public function options($rowid = '') {
        if($this->has_options($rowid)) {
            return $this->_cart_contents[$rowid]['options'];
        } else {
            return array();
        }
    }
     
    /**
     * 清空购物车
     *
     */
    public function destroy() {
        unset($this->_cart_contents);
         
        $this->_cart_contents['cart_total'] = 0;
        $this->_cart_contents['total_items'] = 0;
         
        unset($_SESSION['cart_contents']);
    }
     
    /**
     * 判断购物车物品是否有options选项
     * 
     * @param   string
     * @return  bool
     */
    private function has_options($rowid = '') {
        if( ! isset($this->_cart_contents[$rowid]['options']) OR count($this->_cart_contents[$rowid]['options']) === 0) {
            return FALSE;
        }
         
        return TRUE;
    }
     
    /**
     * 插入数据
     *
     * @access  private 
     * @param   array
     * @return  bool
     */
    private function _insert($items = array()) {
        //输入物品参数异常
        if( ! is_array($items) OR count($items) == 0) {
            if($this->debug === TRUE) {
                $this->_log("cart_no_data_insert");
            }
            return FALSE;
        }
         
        //如果物品参数无效（无id/qty/price/name）
        if( ! isset($items['id']) OR ! isset($items['qty']) OR ! isset($items['price']) OR ! isset($items['name'])) {
            if($this->debug === TRUE) {
                $this->_log("cart_items_data_invalid");
            }
            return FALSE;
        }
         
        //去除物品数量左零及非数字字符
        $items['qty'] = trim(preg_replace('/([^0-9])/i', '', $items['qty']));
        $items['qty'] = trim(preg_replace('/^([0]+)/i', '', $items['qty']));
         
        //如果物品数量为0，或非数字，则我们对购物车不做任何处理!
        if( ! is_numeric($items['qty']) OR $items['qty'] == 0) {
            if($this->debug === TRUE) {
                $this->_log("cart_items_data(qty)_invalid");
            }
            return FALSE;
        }
         
        //物品ID正则判断
        if( ! preg_match('/^['.$this->product_id_rule.']+$/i', $items['id'])) {
            if($this->debug === TRUE) {
                $this->_log("cart_items_data(id)_invalid");
            }
            return FALSE;
        }
        /* 
        //物品名称正则判断
        if( ! preg_match('/^['.$this->product_name_rule.']+$/i', $items['name'])) {
            if($this->debug === TRUE) {
                $this->_log("cart_items_data(name)_invalid");
            }
            return FALSE;
        }
        */ 
        //去除物品单价左零及非数字（带小数点）字符
        $items['price'] = trim(preg_replace('/([^0-9\.])/i', '', $items['price']));
        $items['price'] = trim(preg_replace('/^([0]+)/i', '', $items['price']));
         
        //如果物品单价非数字
        if( ! is_numeric($items['price'])) {
            if($this->debug === TRUE) {
                $this->_log("cart_items_data(price)_invalid");
            }
            return FALSE;
        }
         
        //生成物品的唯一id
        if(isset($items['options']) AND count($items['options']) >0) {
            $rowid = md5($items['id'].implode('', $items['options']));
        } else {
            $rowid = md5($items['id']);
        }
         
        //加入物品到购物车
        unset($this->_cart_contents[$rowid]);
        $this->_cart_contents[$rowid]['rowid'] = $rowid;
        foreach($items as $key => $val) {
            $this->_cart_contents[$rowid][$key] = $val;
        }
         
        return TRUE;
    }
     
    /**
     * 更新购物车物品信息（私有）
     *
     * @access  private
     * @param   array
     * @return  bool
     */
    private function _update($items = array()) {
        //输入物品参数异常
        if( ! isset($items['rowid']) OR ! isset($items['qty']) OR ! isset($this->_cart_contents[$items['rowid']])) {
            if($this->debug == TRUE) {
                $this->_log("cart_items_data_invalid");
            }
            return FALSE;
        }
         
        //去除物品数量左零及非数字字符
        $items['qty'] = preg_replace('/([^0-9])/i', '', $items['qty']);
        $items['qty'] = preg_replace('/^([0]+)/i', '', $items['qty']);
         
        //如果物品数量非数字，对购物车不做任何处理!
        if( ! is_numeric($items['qty'])) {
            if($this->debug === TRUE) {
                $this->_log("cart_items_data(qty)_invalid");
            }
            return FALSE;
        }
         
        //如果购物车物品数量与需要更新的物品数量一致，则不需要更新
        if($this->_cart_contents[$items['rowid']]['qty'] == $items['qty']) {
            if($this->debug === TRUE) {
                $this->_log("cart_items_data(qty)_equal");
            }
            return FALSE;
        }
         
        //如果需要更新的物品数量等于0，表示不需要这件物品，从购物车种清除
        //否则修改购物车物品数量等于输入的物品数量
        if($items['qty'] == 0) {
            unset($this->_cart_contents[$items['rowid']]);
        } else {
            $this->_cart_contents[$items['rowid']]['qty'] = $items['qty'];
        }
         
        return TRUE;
    }
     
    /**
     * 保存购物车数据到session
     * 
     * @access  private
     * @return  bool
     */
    private function _save_cart() {
        //首先清除购物车总物品种类及总金额
        unset($this->_cart_contents['total_items']);
        unset($this->_cart_contents['cart_total']);
         
        //然后遍历数组统计物品种类及总金额
        $total = 0;
        foreach($this->_cart_contents as $key => $val) {
            if( ! is_array($val) OR ! isset($val['price']) OR ! isset($val['qty'])) {
                continue;
            }
             
            $total += ($val['price'] * $val['qty']);
             
            //每种物品的总金额
            $this->_cart_contents[$key]['subtotal'] = ($val['price'] * $val['qty']);
        }
         
        //设置购物车总物品种类及总金额
        $this->_cart_contents['total_items'] = count($this->_cart_contents);
        $this->_cart_contents['cart_total'] = $total;
         
        //如果购物车的元素个数少于等于2，说明购物车为空
        if(count($this->_cart_contents) <= 2) {
            unset($_SESSION['cart_contents']);
            return FALSE;
        }
         
        //保存购物车数据到session
        $_SESSION['cart_contents'] = $this->_cart_contents;
        return TRUE;
    }
     
    /**
     * 日志记录
     *
     * @access  private
     * @param   string
     * @return  bool
     */
    private function _log($msg) {
        return @file_put_contents('cart_err.log', $msg, FILE_APPEND);
    }
}
 
/*End of file cart.php*/
/*Location /htdocs/cart.php*/
?>
